The Interest Assessment Surcharge (IAS) is assessed by the NY Department of Labor to help NY state cover the interest on it’s federal loan. In 2008 and 2009 New York’s Unemployment Insurance Trust Fund did not have enough funds to pay for claims filed by unemployed workers, so the state borrowed from the federal government to cover the shortfall. The debt from the loan is $3.5 billion according to the NY DOL website with $85 million due in interest for 2013. The Interest Assessment Surcharge is how NY state plans to cover the interest on this loan.
Employers in NY state will receive a notice showing an underpayment on their unemployment liability. Under payment is a little confusing since this is actually an additional liability that is due.